Journalists reporting on the failure of 32 critical rods for the new Bay Bridge span continue to confront an insular state Transportation Department that won’t engage in serious discussions of the cause.

The rods were designed to connect pier columns and the deck of the new Bay Bridge span for earthquake stability. Experts agree that they snapped because they were brittle from hydrogen infiltration into the metal.

Caltrans is leading an inquiry into what caused that “embrittlement.” The answer should help determine whether 192 other rods might need replacement because they too could fail. It’s a serious issue of legitimate public concern.

But when the newly confirmed Caltrans director, Malcolm Dougherty, repeatedly put one thing in writing to the Metropolitan Transportation Commission on Wednesday and said another, he did little to instill confidence in the objectivity, transparency and competency of his organization.

So far, most information on what might have caused the embrittlement has come from excellent investigative reporting by journalists Lisa Vorderbrueggen of this newspaper and Jaxon Van Derbeken of the San Francisco Chronicle.

In a recent editorial, we summarized their work and identified key issues they raised that Caltrans needed to address. On Wednesday, Dougherty provided brief point-by-point responses during his presentation to the commission.

But the information in the PowerPoint slides he used didn’t jibe with what he said verbally to the commission or, after the meeting, to reporters. (For a detailed comparison, go to this column at contracostatimes.com/daniel-borenstein.)

The slides mostly dismissed the issues the journalists had raised. Dougherty’s comments eventually acknowledged that they had brought up four legitimate points and that he didn’t know if a fifth was valid.

Caltrans shouldn’t be leading this investigation of what went wrong. The agency might have been a key contributor to the failures, as an independent metallurgist reported last week. Clearly, neutral outside experts should conduct the probe.

For now, however, Caltrans is running the investigation, using a consultant for the bridge contractor, a Caltrans engineer and a Caltrans consultant. And even though Dougherty just won state Senate confirmation on Monday after promising he would correct Caltrans’ insular culture, the agency refuses to make its knowledgeable people available for serious discussions with reporters.

Instead, they rolled out Dougherty for an MTC presentation and quick news conference for television sound bites before whisking him away, leaving behind a series of evasive and self-contradictory answers.

Consider, for example, some of the issues the two reporters raised:

Documentation: When the rods were produced, documentation of heat-treating was missing. Dougherty’s slides highlighted other record issues, but skipped this one. Questioned later, he acknowledged that there were no records.

Second heat-treating: Because of the missing paperwork, the rods were heat-treated a second time, which might have made them more susceptible to embrittlement. Dougherty’s slides contradicted that, saying the two heat treatments did not result in additional susceptibility. But Dougherty said the second heat-treatment could have made the rods more susceptible.

Galvanization: The rods were dipped in molten zinc to protect them from marine air. Such galvanization could lock in hydrogen during the process. Dougherty’s slides suggested the concern had been addressed during the galvanization. But, in his comments, he agreed with reporting that galvanization could have trapped hydrogen inside the rods.

Tests not performed: Magnetic particle testing might have exposed cracks that made the rods more susceptible to embrittlement. Dougherty’s slides say the test is not a standard industry requirement and does not detect hydrogen embrittlement.

That evaded the point. No reporting said the test would have been a direct detector of embrittlement. The issue was whether the test might have identified cracks that later made the rods more susceptible. Dougherty echoed the slides in his comments. But when questioned further during the news conference, he said he didn’t know if magnetic particle testing would have been a helpful.

Dougherty, who declined an interview for this column, and his agency are too dismissive of journalists’ important role. Vorderbrueggen and Van Derbeken, relying on outside experts, have provided the public and elected officials far more insight into the embrittlement problem than Caltrans has.

Dan Borenstein is an award-winning columnist and editorial writer for the Bay Area News Group. He has worked for the East Bay Times and its affiliated newspapers since 1980, including previous assignments as political editor, Sacramento bureau editor, projects editor and assistant metro editor. A Bay Area native, he holds master’s degrees in public policy and journalism from University of California, Berkeley.

In closed door talks, Sen. Dianne Feinstein agreed to a major new water policy for California that sells out the Delta and guts Endangered Species Act protections. Sen. Barbara Boxer is fighting the good fight to remove the rider from her comprehensive water infrastructure bill, but it may take a presidential veto.